1. This invention relates to a recording apparatus and a motor control device which is highly suited to the recording apparatus.
2. Description of the Relates Art
Known recording apparatuses for recording signals on a recording medium includes electronic still picture camera arranged to record a video signal, for example, on a disc-shaped magnetic sheet. In the electronic camera of this kind, concentric circular tracks are formed on the magnetic sheet or disc which is employed as a recording medium by recording signals with a recording head while shifting the position of the recording head relative to the magnetic sheet by allowing the latter to rotate at a high and constant speed. It is necessary for the apparatus of this kind to minimize a time lag after a shutter release button is pushed for a start of recording and before an actual start of recording. To meet this requirement, the build-up of rotation of the magnetic sheet must be quickened as much as possible. For that purpose, it is conceivable to apply a maximum amount of electric energy to magnetic sheet driving means at the building-up time of rotation of the magnetic sheet. The same concept applies not only to the electronic camera but also to any other recording apparatus that is required to have a minimal degree of time lag at the start thereof.
However, in the conventional recording apparatuses in general, the time lag minimization at the start of the above-stated driving means for shifting a relative position between the recording medium and the recording head is not always necessary. For example, in the case of the electronic still (picture) camera, the magnetic sheet is caused to begin to rotate for the purpose of detecting the presence or absence of any previous record in each of recording tracks on the magnetic sheet. Although it is preferable to have the above-stated time lag arranged to be short also in that instance, the necessity for a short time lag is not so strong as compared with the start of actual recording after the shutter release button is pushed. If, despite of such different occasions, the above-stated time lag minimizing starting operation is always indiscriminatingly performed, a waste of a limited battery capacity would result in an excessive drop of a power supply voltage causing a malfunction of some other related device.
This problem has existed not only with the electronic still picture camera but also with other recording apparatuses of the kind arranged to perform recording by changing the relative position between the recording medium and the recording head.